Touch sensitive systems refer, in general, to systems that detect and respond to multiple simultaneous points of contact on a surface. Typically, a touch sensitive system is incorporated within an electronic device in the form of a touch screen display that allows a user to both view and manipulate objects using one or more inputs that are in contact with the screen. Examples of electronic devices in which a touch sensitive system has been used include computer tablets, personal digital assistants (PDA), and cell-phones, among others. A variety of techniques are available that enable touch sensitive systems. For example, some touch systems identify surface contact by detecting changes in heat, pressure, capacitance or light intensity.